Ocean currents show global intensification of weak tropical cyclones
Ocean currents show global intensification of weak tropical cyclones
复制标题
DOI：
10.1038/s41586-022-05326-4
复制
发表时间：
2022-11
期刊：
影响因子：
64.8
通讯作者：
Guihua Wang;Ling-long Wu;W. Mei;S. Xie
中科院分区：
文献类型：
--
作者：
Guihua Wang;Ling-long Wu;W. Mei;S. Xie
理论和数值模拟表明，热带气旋（TC）将随着海洋温度的上升而加强。尽管模型已经就预计的TC增强达成了广泛的一致，但在除北大西洋以外的所有洋盆中，观察到的TC强度趋势仍然没有定论，并处于激烈的争论之中，在北大西洋，飞机侦察数据大大减少了不确定性。由于暴雨、云层、碎浪和浪花的影响，传统的卫星估计不足以准确地确定热带气旋强度的趋势。在这里，我们表明，弱TC（即，热带风暴的1类TC的基础上的萨菲尔-辛普森规模）在1991年至2020年期间，在所有海洋盆地加强，基于大量的高度精确的海流数据来自表面漂流。这些漂流者在15米深的水下安装了“圣袜”锥管，以减少海气界面过程引起的偏差，从而准确测量近地表海流，即使在最具破坏性的TC下也是如此。海流速度在全球范围内呈现出每十年约4.0 cm s-1的强劲上升趋势，对应于TC强度每十年1.8 m s-1的正趋势。我们的分析进一步表明，全球TC在整个强度分布中都有所加强。这些结果作为历史基线，对于评估模型物理学、模拟和预测至关重要，因为最先进的气候模型无法完全复制这些趋势。
Theory and numerical modelling suggest that tropical cyclones (TCs) will strengthen with rising ocean temperatures. Even though models have reached broad agreement on projected TC intensification, –, observed trends in TC intensity remain inconclusive and under active debate, , , –in all ocean basins except the North Atlantic, where aircraft reconnaissance data greatly reduce uncertainties. The conventional satellite-based estimates are not accurate enough to ascertain the trend in TC intensity,, suffering from contamination by heavy rain, clouds, breaking waves and spray. Here we show that weak TCs (that is, tropical storms to category-1 TCs based on the Saffir–Simpson scale) have intensified in all ocean basins during the period 1991–2020, based on huge amounts of highly accurate ocean current data derived from surface drifters. These drifters have submerged ‘holy sock’ drogues at 15 m depth to reduce biases induced by processes at the air–sea interface and thereby accurately measure near-surface currents, even under the most destructive TCs. The ocean current speeds show a robust upward trend of ~4.0 cm s−1per decade globally, corresponding to a positive trend of 1.8 m s−1per decade in the TC intensity. Our analysis further indicates that globally TCs have strengthened across the entirety of the intensity distribution. These results serve as a historical baseline that is crucial for assessing model physics, simulations and projections given the failure of state-of-the-art climate models in fully replicating these trends.